Locking devices



Dec. 9, 1958 c. b. TUCKER 2,363,210

LOCKING DEVICES Filed July 50, 1952 3 Sheets-Sheet 2 &

CHARLES D. TUCKER I B? ZZZ/fizz;

ATTORNEY INVENT'OR' Dec. 9, 1958 Filed July 50, 1952 FIG. I0. I

FIG.I2.

C. D. TUCKER LOCKING DEVICES- 3 Sheefs-Sheet 3 FIG.|5.

INVENTOR CHARLES D. TUCKER ATTORNEY United States Patent LOCKING DEVICESCharles D. Tucker, Cochranton, Pa.-, asslgnor to Mc- Crosky ToolCorporatiomMeadville, Pa., a corporation of Pennsylvania.

Application July 30, 1952, Serial No. 301,636 2 Claims. (Cl. 29-105)This invention relates to devices for locking or adjusting the blades orcutters of mills, boring bars, and the like, wherein the cuttingjorboringoperation is accomplished by a rotation of .the. tool body orholder. They are also applicable for thesame purpose in conjunction withtoolsand stationary or non-rotating tool. holders, such as are found inlathes, shapers and inserted-bit broaches. While the invention will bespecifically described in connection with the tool body of a mill itsapplication thereto is not to be. construed as a limitation thereof forthe reasons just given.

More particularly, the present invention is concerned with an effectivebut relatively inexpensive blade-locking unit to be substituted forthose in the prior art. Basically, this new unit consists-of a metalbody that is partially divided transversely intottwojparts which carryone or more screws operable to. distort the body to produce a lockingaction when the unit is in position beside a cutter blade.

In its general aspects the, invention contemplates the provision of oneor'more, blade receptacles in a tool body or holder for the reception ofone or more cutting blades or tools and a corresponding number of blade.locking devices, each constructed in the form of an assembly readilyinsertible and removable as a unit.

It is the primary object of the present inventionto devise a lockingunit thatcan be distorted tov fulfill its purpose by changing its shapewithout appreciable change in its external size. In this connection, itis an object to form the unit body of a material that will spring backto its original shape when released from theforces creatingthedistortion.

Another major object of this invention resides in the provision of aclamping block that can be distorted to create three separate externalpoints, lines or areas of outward force application; the purpose-of thisbeing to obtain the full desired locking action automatically, and thisin spite of errors in shaping the block and the walls of the tool bodyand blade against which it is designed to react. Thus, substantialmachining tolerances are permissible.

It is a further object to design a slotted locking-member in such mannerthat the slot is concealed when in i use and hence closed against theentry of dirtand chips that might clog it and prevent or impede movementof the parts.

It also is an object to provide a locking unit body with a transverseslot that extends to a greatdepth from one side of the body towards theother and that is disposed approximately half way between the top andbottom of the body; all for the purpose of facilitating actuation of alocking screw and of assuring the three-zone contacts previouslymentioned.

A still further object is to slot a clamping body so as to form a pairof integrally connected lever arms or leaves, and to provide one or theother of such arms with internal screw threads for association with ascrew so that the arms are forced either towards each other or apart.

In any case, whether. the screw is placed undertension or compression,the body is distorted to createthreev external zones for application ofclamping fOITCfiSr,

Continuing with the. foregoing generallobject, if a. headed screw isutilized the head mayhaye a universal;

seat, providedeither by machining, the bottom of the head spherically orby placing ajbeveled washer'orring against the, bottom of a:conventional screwhead.

It is a stillfurther object to' create resilience of thelocking body byappropriate; heat treatment-for -the material selected Tsothatxthe partswill spring, backxto initial.

shape after distortion; and, in this connection, to incorporate a snapring orsplit washer sometimesinlhe assembled unit,- particularly wherethe unitahas a'large and heavy clamping; body, toaprovide anabutmentagainst which the screw head may react to augment the inherentspringaction of the distorted lever arms when they .are;

released: It should. be understood, however, that the washer may beutilized alone to aid in restoring;deadarms to initial shape orposition.

Another; object is. to incorporate the'invention inan elongated,substantially rectangular bar designed; to be:

placed adjacent a cutting blade; this bar-shaped block beingslottedlengthwise to format pair of leaves for association witha-plurality of spaced operating or clamp ingscrews.

The foregoing and further objects: of my invention should bereadilyapparent. from a study of the;fol1owing description when taken inconjunction. with theaccompanying drawings, wherein:

Figure 1 shows,.in side elevation.andxlookingfintothe slot, one oftheipreferred embodiments;olfi the lockingi;

unit of this invention;

Figure 2. represents; a section takenvertieally on the plane .ofline'24-2, Figure 1.

Figure 3 illustrates, chiefly in section, the unit: of. Figures 1 and; 2in association with. a blade ofgamillingy cutter, head, the screw havingbeen. tightened,- to eifectv a; look. (In Figs. 3 and 4; possiblernachining errors:are inw the slot is cut into the round surface insteadof the. flat side of the block.

Figures 7 and 8 correspond with Figures 5 and 6, the essential.difference being that, the screwis positioned eccentrically instead ofcoaxially with respectztothe curved surface of theblock.

Figure 9 illustrates, in vertical section, a unit (usually,

heavier than normal) in which a split ring, has been;

added.

Figures IOand ll show, in vertical section, twoways of providingasphericalsurface at the bottom ofithelock-y ingscrew head of any. of thepreceding forms ofthe invention.

Figure 12 is a section. illustrating a modification in;

which a headless screw is provided.for;the clamping action; and Figure13, shows this sameembodiment after the screw has been placedundercompressiontoeffeet a lock.

Figure 14 is a planview of a further embodiment ofthe inventioncomprising an elongated and slotted bar in association with a blade of amilling cutter body.

Figure 15 is a sectional view taken on the planeoflline 1515, Figure 14.

to it a substantial resilience; and this block, which may vary in shape,has a transverse (approximately horizontal) Patented 1 Dec 9; 1958 3slot 21 of substantially uniform width that divides it into a pair oflever arms or leaves 22, 23, bridged by an integral web or rib 24 thatcontains a cantilever fulcrum for a locking action presently described.

The arm 23 has an internally threaded hole .25 and the arm 22 has aplain hole 26 aligned with but larger than hole 25. The arm 22 has acounter-bored recess 27 aligned with both holes and of enough largerdiameter to provide a horizontal annular shoulder 28.

Figure 4 shows that the block has a cylindrically curved wall 30intersected by a vertical fiat face 31, the purpose of this shape beingto fit the block freely into a correspondingly shaped recess 32 in atool body 33 (sometimes rotary) that carries a cutting blade 34.Normally, the recess 32 is accurately formed, but it will be appreciatedthat it may have substantially errors in machining, this also being trueof the block.

A screw comprising a round-cap and hex-recessed head 35 and a shank 36has external threads 37 for reception in the hole 25. The head and shankhave clearances in the recess 27 and the hole 26, respectively. Thenormal position of these parts is shown in Figures 1 and 2, with thehead lightly engaging the shoulder 28. When the screw is tightened toplace it under tension the free ends of the lever arms 22, 23 are drawntoward each other to narrow the slot 21 and distort the entire body 20;the fulcrum for this action being in the web 24 and creating three zonesof force application A, B, and C. These zones are very important and, asseen in Figures 3 and 4, are theoretical points or lines but, probably,actually result in small deformed surface areas that produce exaggeratedclearances 38 and 40 and also cock the screw head 35 to produce aclearance 41 (likewise exaggerated).

The action of the three zones A, B and C is triangular and automatic,thus under normal conditions causing the contact edges of the block 20to bite into the matching surfaces of the recess 32 and the blade 34.The scheme is not just to latch the unit against radial outwardmovement, but to automatically adjust and lock itself with a tripodaction into a socket that may have been created with appreciablemachining tolerances. For example, although recess 32 is larger inFigures 3 and 4 at the bottom than at its top (as might occur inpractice) the unit has locked itself securely at the three points A, B,C, and has done so without appreciable change in its body volume.

The cylindrically curved walls of the block 20 and the recess 32 permitthe block to rockably adjust itself to ensure that the full width of itsflat face contacts the blade in the locking zones B, C.

A further advantage resides in such arrangement of the slot 21 withrespect to the other parts of the combination that its openings arefully concealed, except for small clearances; thus it cannot receive oraccumulate chips and foreign material that might clog it and preventfree manipulation of the screw and the leverage arms.

In the foregoing treatment of the invention, the slot 21 was cut orotherwise formed into the flat side of the insertible body 20. It (theslot) may also be oppositely directed, coming into the rounded wallsurface as shown in Figures 5 and 6. In either case and particularlythat of Figures 5 and 6 because of the tightening screw possibly beingtoo close to the fulcrum web 24 to give adequate leverage, the screw maybe disposed off center as in Figures 7 and 8 (the offset depending uponwhich direction the slot is cut into the block 20) to increase thelocking leverage exerted by the lever arms 22, 23.

Heat treatment of the metal is regarded as highly important in mostcases, but in some instancesparticularly where a heavy unit isusedspring action alone may be inadequate to restore the lever arms totheir initial positions when the device is to be unlocked. Accordingly,as in Figure 9, the counterbore 27 may have an annular groove 44 cutinto it for reception of a snap ring 45. Thus, when the screw isretracted its head 35 engages the snap ring and forces the arms 22, 23apart. This action, of course, can take place without any augmentingspring action in the event the block has little or no resilience.

Figure 10 illustrates an expedient for assisting the rocking action ofthe screw head, consisting in the provision of a spherical formation 46at the bottom of the head for universal movement within a complementallyshaped seat formed by the modified shoulder28a.

Instead, as in Figure 10, of utilizing a special screw, one withstandard head will sufiice if a beveled washer 47 is provided to seatuniversally upon the shoulder 28a, this being shown in Figure 11.

The modified form of Figures 12 and 13 consists of a block 26a, slottedas heretofore described to provide a pair of normally parallel arms orleaves 22a and 23a. In this case the arm 23a is solid and the other armbored and tapped to receive an unheaded locking screw 50. The latterbears against the top of arm 23a and, when tightened, forces the armsapart, the screw thus being under compression rather than tension. Here,because of this different action the zone A occurs at the open end ofthe slot, and rocking zones B and C are transferred to points or edgesat opposite corners. The functioning of this unit is essentially thesame as the other type. The slot may be cut into either the flat orround side surfaces of the block; and the screw may be either centeredor eccentric.

Figures 14 and 15 illustrate how the invention lends itself for use inan elongated bar-type locking device. A tool body 52 carries a cutter53. The recess or slot for the latter can be widened to form a fulltransverse socket 54 for reception of a rectangular block in the form ofa bar 55. This bar is slotted at one side from end to end to form theslot 56 substantially midway between its top and bottom. A plurality ofscrews 57 are added and, when tightened (Fig. 15), create the importantthree zones A, B, C in the form of parallel lines of contact for lockingpurposes.

The embodiment of Figures 14 and 15 may be modified to add or tosubstitute some of the novel features noted in describing the precedingforms.

What is claimed is:

1. The combination with a cylindrical tool body having a recessextending inwardly from the periphery thereof and a blade mountedtherein for adjustment radially of the tool body; of a blade lockingdevice comprising a resilient metallic block fitted endwise into saidrecess between said blade and a wall of said recess, said block having adeep slot located between its ends in a plane transversely of saiddirection of adjustment to form a pair of spaced superposed integrallyjoined lever arms, and means carried by said arms and adapted to causerelative movement between said arms for moving the free ends of the armsin substantially arcuate paths extending in the general direction inwhich the blade is adjustable, whereby said block is expanded to causeat least one edge of the free end of each arm and an opposite portion ofthe block to wedge between said wall of said recess and said blade withsubstantially line contacts to lock the blade in the tool body, saidline contacts extending in a direction normal to the direction ofadjustment of the blade in the tool body.

2. The combination with-a tool body having a recess extending inwardlyfrom a surface thereof, a blade mounted in said recess for adjustment ina direction outwardly of the surface of the tool body; and a bladelock.- ing device comprising a resilient metallic block fitted endwisein said recess between said blade and an opposed side of said recess andhaving a plane surface to engage said blade, said block having a deepslot located between its ends in a plane transversely of said directionof adjustment and through the plane surface thereof to form a pair ofspaced superposed lever arms integrally joined by a web portion of theblock, and a headed actuating screw having its shank extending freelythrough the upper arm and into threaded connection with the lower armfor moving the free ends of the arms toward each other in substantiallyarcuate paths extending in the general direction in which the blade isadjustable, whereby the edges of the arms remote from the slot areforced into substantially line contact with the blade and an externalportion of the block adjacent the slot and at the side of the blockopposite the free ends of the arms is forced into substantially linecontact with the wall of the recess to lock the blade in the tool body,said line contacts extending in a direction normal to the direction ofadjustment of the blade in the tool body.

References Cited in the file of this patent UNITED STATES PATENTS WilesJan. 4, 1876 Randall et a1 Feb. 12, 1878 McKay June 6, 1911 Vokal Aug.11, 1925 Westgard Sept. 13, 1927 Miller Mar. 13, 1934 Jostich Oct. 12,1943 Sheldrick Oct. 18, 1949 Skeel Apr. 3, 1951 FOREIGN PATENTS FranceJan. 6, 1915

